Figure 3

Comparison of the region of the 66.3 kDa protein, which differs significantly between the one chain and two chain variants. The structures are shown in the putative order of the maturation process starting at the top. The most significant differences concern the residue range N239-C249. This range and additionally the adjacent residues K237, T238 and S250 as well as the side chains of E507 and R531 and a glycerol molecule are shown in stick mode with the surrounding electron density of a F_oF_c simulated annealing omit map at a contour level of 5.0 s (carbon, oxygen and nitrogen atoms in green, red and blue, respectively). The bound Na⁺ ion is shown as a blue sphere. Interactions between the sodium ion and C249 or S246 are indicated by black dashed lines. For orientation, L231-N236 and A251-K254 are shown in cartoon mode.